Posted
by
timothy
on Thursday February 18, 2010 @04:42PM
from the yes-yes-it's-not-the-world-record dept.

kkleiner writes "Cube Stormer is the latest creation from Mike Dobson, aka Robotics Solutions, and not only is it made entirely out of Legos, it can solve any 3x3 Rubik's cube in less than twelve seconds. Often it can finish in less than five! This thing looks bad-ass and is incredible to watch."

When I was a small child of 4 or 5 in the early 80's, my Dad got a Rubik's Cube for Christmas. He found it amusing. A few days later I brought it to him, completely solved. He was amazed! Not only had his genius son shown remarkable problem solving skills at such a young age, I had even managed to put a few of the stickers back on straight.

Okay, it's not FAKE but it's completely and entirely dishonest. I can solve the rubik's cube in about 20 seconds over an average of 12 solves, so I have a thorough understanding of human speed-solving. Computers, on the other hand, would go for some idea solution that a human brain is not capable of producing. This is especially true since the robot in this video moves EXTREMELY slowly, about 1-2 turns per second on average. Human hands can EASILY sustain 3-5 moves per second. This computer, to solve the Rubik's cube in 2 seconds as in the first part of the video, or 4 seconds as in the second part of the video, would have to be able to solve the cube in 4-10 moves. The optimal solution for solving a rubik's cube has already been bounded at about 18 moves (look it up).

Still don't believe me? Start watching and replay the video from 30s onwards. Freeze the video when the timer starts at 0:00 and look at the cube, it is actually a single 90 degree rotation away from a fully solved state.

The 4s video beginning at 1:07 shows several rotations of the WHOLE CUBE without making any actual moves, then does 4 turns and solve it, which means that it wasn't anywhere near a scrambled state to begin with.

More evidence that it's fake? Is there any information on this other than a 2 minute video on youtube?

The optimal solution for solving a rubik's cube has already been bounded at about 18 moves (look it up).

Only in the worst possible configuration of the cube. 18 moves can't be the lower bound for every cube, because there exist many configurations that can be solved in less than 18. (Like the one you mentioned at 30s) If you'd read the rest of the wiki article you probably just consulted you would have seen that there even configurations that need over 20 moves too.

As for turning the cube then solving it in 4 moves, look at the computer and note a single view of the cube. The machine has to determine the star

It's dishonest because for both the "2s" and "4s" solve of the cube, the cube was not fully scrambled. In fact, for the 2 second solve, the cube only had one single turn on it when the timer started. It is dishonest because he CLEARLY and obviously did not scramble the cube for both the 2 second and 4 second time. Look at the video at 30s and freeze it at the start of the timer and you'll see exactly what I mean. I can't honestly believe that you don't know what I mean by "dishonest" if you haven't done thi

If you watch carefully, the "Full Solve", which states such and claims to be a "totally random cube (Honest)", takes 10.75 seconds, including inspection. The 2.01 second solve is a demonstration of the MINIMUM time required for "inspecting and making one twist" on an unsolved cube. It is the blogger, and not the video, who makes the claims of solving in 2.01 seconds, and while it technically is a solve, the inventor rightfully does not claim such. The world record human solve of 7.08 seconds is not including the untimed inspection period. I would not consider this a dishonest video, since the video does not claim anything but the 10.75s solve to be a real solve, which by the rules of the second video's competition, would actually be an 8.74s solve....

It's dishonest because for both the "2s" and "4s" solve of the cube, the cube was not fully scrambled. In fact, for the 2 second solve, the cube only had one single turn on it when the timer started. It is dishonest because he CLEARLY and obviously did not scramble the cube for both the 2 second and 4 second time.

This isn't dishonest. I watched the video and saw that the machine can solve a trivial problem in one move. The video didn't disguise this in the slightest. You can see a more complex configuration being solved elsewhere in the video and this obviously takes more time.

Look at the video at 30s and freeze it at the start of the timer and you'll see exactly what I mean. I can't honestly believe that you don't know what I mean by "dishonest" if you haven't done this simple task for me.

At 0:30 I see a cut from one sequence to another. I didn't think I was watching a real demonstration until I saw a start-to-finish run without any cuts.

And yeah, you were right about the 18 moves thing, I was quickly looking for a number to back up my argument. The fact that 18 is actually lower than the optimal lower bound strengthens my argument instead of weakening it, though.

No, it doesn't. Your original argument seemed to be that 18 moves is the lower bound for so

He isn't claiming that it is fully scrambled in the 2s one - for the one immediately after he specifically says to get ready for a "full solve" and has big letters come up saying the NEXT CUBE is a "totally scrambled cube". The 2s was just a demonstration of the machine moving and is implied as such. You could maybe make a case about the 4 second one, but I'm not sure he's claiming that one to be a full scramble either.

Being made of Lego raises the coolness of an object to it's own power. So if a machine solving a Rubik's Cube had a coolness factor of say, 100, then a machine solving a Rubik's Cube MADE OF LEGO would be 100 ^ 100, or:

I think your definition of "fake" and mine differ. The video is certainly not fake. It's a Lego machine that can solve a Rubics Cube that is being blogged about by some random overzealous blogger. The 2 and 4 second solves were probably the engineer running test cases where he took a solved cube and rotated it a certain number of times to see if the machine would then solve it in the same number of rotations. It's fairly obvious that the machine isn't capable of solving a random cube in 2-4 seconds beca

The next to last solve (at 41s) takes 21 moves*, and is the only cube claimed to be random... thus, I don't see any dishonesty. It takes around 1.9 seconds to analyze, about 0.4 seconds to reset/process, and the remaining 8+ seconds to solve. Therefore, it makes on average between 2 and 3 turns per second.

Humans do not include inspection time in the speed calculation (at least, that's the case in the accompanying video of the world record). An apples-to-apples comparison, therefore, would be the human time at 7 seconds and the robot at a little over 8. I couldn't follow the world-record video, but I think I saw at least one mistake (a move followed by the opposite move) and a little hesitation. So, you're probably correct in the 3-5 moves per second for humans.

*21 includes twice that the computer simultaneously moves two faces, each counted as two separate moves. 180 degree moves are counted once.

Are you sure? Just about every Asian I know can do it that quickly, and they make up about 30% of the world's population.

Interesting comment. East Asians have a higher visuospatial IQ. It would make sense that solving a Rubik's cube would play to their strengths - it's pure visuospatial ability. Your anecdote rings true with me - I remember being amazed at how quickly a group of average Japanese students could play Tetris on the Gameboy. They were able to play it indefinitely at the fastest level. The abil

Unfortunately, the linked to post and video doesn't give much details. Naively, I expect that the computer program is first figuring out very quickly what the series of movements to solve the cube and then implementing those. There are around 4 * 10^19 possible configurations for a Rubik's cube, but the group theory allows one to work out what steps to take without having to do very exhaustive searches since the Rubik's group is very well-behaved. However, this assumes one is in an actually solvable configuration. I'd be curious to find out if they've debugged the device well enough to make sure it doesn't hang or get in some infinite loop if one gives it an unsolvable cube (not all possible permutations of squares are solvable. Most trivially, edges need to stay on edges, corners on corners and centers on centers. But some configurations are still not solvable. For example, if one swaps two center stickers it isn't hard to see that that lays outside the Rubik's group of reachable permutations).

They probably didn't debug it much, but in actuality - most of it is pattern recognition. If you look straight down the corner of one Rubiks cube, you will see 3 faces of it, and that is all you actually need to solve the Rubiks cube. All the pros merely remember the patterns and the steps required to solve each pattern. Rotate the cube 90 degrees and the pattern still exists, even though things are in a different shape.

Really, the programming side of this isn't that impressive once you know how Rubiks cube solving is done. I'm more impressed at the speed, which I've normally found Lego technic and Mindstorm products to be a little laggy in commands and slow to operate, keep in mind though, that was the stuff I used like 7 years ago.

Although I assume you're being sarcastic, as Rubik's cube tournaments used to be somewhat widespread, but yes, there are professional SCRABBLE players for chrissake. I even saw a documentary about them once. They really are as pathetic as they sound.

(No, seriously, I am. Scrabble has a lot of depth to it when played on a higher level that you are completely ignoring. Don't be so quick to dismiss something just because you don't know much about it.)

Yeah, I don't know anything, I just watched the private lives of national competitors. I judge them lacking. That is my prerogative.

Also, Scrabble lacks depth at higher levels. National competitors learn spellings but not necessarily meanings, which completely bastardizes the entire point of language. National Scrabble competitors essentially live or die by the number of combinations of seven letters they know are valid. To me that is a disgusting travesty, and quite frankly after watching Word Wars I di

Supposedly there is a set series of moves that will solve and brand new (ie just opened Rubik's cube). I have seen videos of people solving one behind their backs, blind folded. The set series of moves has some reasoning.

I usually took it apart and put it together with the sides matching. There were a few times I used a baseball bat to 'solve' the cube. Good stress relief that way.

It looks pretty simple to me. You put it in and it snaps shots of the 6 sides of the cube. Those are interpreted by the computer which probably uses a standard solving algorithm. The solution is translated into movements for the robot, and off it goes.

My guess would be if it was impossible to solve, it wouldn't start doing anything, the software would complain. No Rubik's cube is impossible to solve without physically messing with the cube (as you pointed out, swapping stickers for example). If you start w

You put it in and it snaps shots of the 6 sides of the cube. Those are interpreted by the computer which probably uses a standard solving algorithm. The solution is translated into movements for the robot, and off it goes.

I'm stunned. And here I was thinking it worked by magic. Is that REALLY how it's done?

I can't understand why this is a "Lego" robot.The pads are Lego the rest of the Lego is total cheap fluff. If I stick a few pieces of Lego on my car does that mean I drive a Lego car?Maybe it is some cheap promo.

You know, I have a great Lego pizza oven. It's made entirely of Legos. Well, except for the metal box, heating element, wires, plug, and a few other things, of course. This is obviously some new use of the word "entirely".

People I know *don't* consider it as a mass noun. Ice makes sense as a mass noun since the same term applies to quantities ranging between ~10 molecules to an entire moon of an outer planet. For Legos, OTOH, it makes zero sense to use a mass noun because you're almost always concerned with a number of pieces from 1 up to a couple of hundred. In fact, you're often occupied handling just a single Lego piece, so not having a singular version available would be highly irritating.

In a few minutes I'm going to go drive home in a Ford. Just one Ford. Mine. Then there will be a Ford in my driveway at home. If my son still played with Legos - he doesn't much nowadays - I might play Legos with him. But I won't today.

To make it easier on all of you pedantic types how about if instead of pluralizing Lego to Legos. We'll just abbreviate "Lego Bricks" to something that rolls off the tongue a little easier. How about "Legos"?

I wouldn't go so far as to call it lame but it pisses me of when people say such and such is made of legos with the
implication that somehow that makes it more difficult.
I'd be more impressed if he had fabricated the parts himself than if he used premade parts that snap together. now if had used regular bricks for the whole thing that would be a different story.

I have a Mindstorm, and I'm fairly certain it cannot be programmed to do OCR... I'm pretty sure the Sudoku picture is a joke. The Mindstorm can recognize colors by shining 3 different color LEDs on a spot and measuring the light with a photocell; it is just hard to believe even a network of Mindstorms could solve a Rubick's cube that quickly, even if they are fast enough to emulate a Segway. I'm pretty sure they have a much faster computer driving the Mindstorms.

programming it to write with a pencil must have been incredibly tough.

Pen-plotter control algorithms were ancient and well-documented 30 years ago when I saw the source code for a hobbiest homebrew version (about 1k lines of assembler) in Byte Magazine (I think... 30 years and all).

mind you, the cubic solver is nice looking and has a lot of attention paid to making it look good, but it seems to be using a netbook. The sudoko seems to be using ONLY its onboard lego controller, and it has that human touch of writing with a real pen that makes it spooky. The math may be simpler, the robotics seems far more complex. I can almost imagine that robot driving around looking for dropped newspapers to solve the puzzles:P

The sudoko also wins for me because while all the principles involved are